Getting in the "invention surviving in your brain", to a actual functioning method is called "reducing the invention to practice", and almost invariably contributes to the discovery of the number of issues with details which are not clearly evident when only residing in the mind. Making a model or prototype http://marcollhz31260.tinyblogging.com/Invention-Prototypes-and-Models-Valuable-Tools-For-your-Small-Inventor--30217193